|CHEN, JING - US Department Of Agriculture (USDA)|
Submitted to: Analytical and Bioanalytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2017
Publication Date: 1/26/2018
Citation: Chen, J., Park, B. 2018. Label-free screening of foodborne Salmonella using surface plasmon resonance imaging. Analytical and Bioanalytical Chemistry. 410:5455-5464. DOI:10.1007/s00216-017-0810-z.
Interpretive Summary: An estimated 95% of the foodborne infections are caused by 15 major pathogens including Salmonella. Rapid and simultaneous screening of these pathogens could benefit public health at low costs. Surface plasmon resonance imaging (SPRi) provides an efficient and cost-effective platform for screening foodborne pathogens. In this study, we developed a method for Salmonella using SPRi. The method showed good selectivity towards the Salmonella serotypes most frequently associated with foodborne outbreaks. The optical method was used to successfully detect low levels of Salmonella directly from chicken rinsate rinse sample enrichment without further sample treatment.
Technical Abstract: Since 15 pathogens cause approximately 95% of the foodborne infections, it is desirable to develop rapid and simultaneous screening methods for these major pathogens. In this study, we developed an immunoassay for Salmonella based on surface plasmon resonance imaging (SPRi). The sensor surface modification and SPRi flow conditions were optimized. The method shows good specificity for Salmonella, including 3 serotypes most frequently associated with outbreaks. Limits of detection were found to be 2.1×106 CFU/mL in phosphate buffered saline and 4.1×106 CFU/mL in the presence of chicken rinse matrix with 8.9×107 CFU/mL of indigenous microflora. The condition of antibody array regeneration was optimized for sequential sample injections. Finally, the SPRi immunoassay was used to detect Salmonella directly from artificially spiked chicken carcass rinse samples. As low as 6.8 CFU/mL of Salmonella could be detected after overnight enrichment in buffered peptone water, demonstrating the potential in streamlined pathogen screening with minimal sample preparation and without detection labels.